폐쇄성 수면무호흡증 환자에서 신경인지기능 이상과 수면요인과의 관련성

Neurocognitive Dysfunction Related with Sleep Factors in Patients with Obstructive Sleep Apnea

We aimed to review the neurocognitive dysfunction in obstructive sleep apnea (OSA) and to clarify its relationship with hypoxemia, sleep fragmentation and daytime sleepiness. The disordered breathing during rapid-eye movement sleep (REMS) was recognized as a correlate of the neurocognitive impairment in OSA. Among sleep characteristics of OSA, intermittent hypoxemia (IH) was discussed in terms of possible mechanisms such as the abnormality of ventilatory drive, vasculopathy and oxidative stress. Specific brain damages in the frontal lobe and the hippocampus was also addressed. The OSA patients often experience decline in multiple domains of neurocognitive function. Particularly, decline in attention, executive function, constructional ability, or psychomotor performance was reported to be highly associated with IH. There have been some debates on the effect of daytime sleepiness on neurocognitive function. Persistent impairment in executive function and psychomotor performance after the treatment of OSA suggests an irreversible brain damage. A standardized instrument needs to be developed to evaluate each domain of neurocognitive function, and to measure the severity of OSA and its treatment response. Further studies on the relationship of REMS with the neurocognitive function are necessary.